Jelavic has lost his starting place both at club and international level after a dip in form that has seen him score just three times in 2013.

The 28-year-old hit 11 goals in his first 16 games for Everton after arriving from Rangers for 5.5 million pounds in Jan. 2012.

But he has not found the net for club or country in the last nine months -- having scored for Everton in a 5-1 FA Cup win at Cheltenham in January and a 2-0 Premier League victory over Manchester City in March, and for Croatia in a 4-0 friendly win against South Korea in February.

Jelavic and Netherlands international defender John Heitinga have both been linked with January moves away from Everton as they seek regular first-team football in a World Cup year.

Martinez said earlier this month that he would do all he could to help the Dutchman find games, and has extended that offer to Jelavic -- although he would prefer both to stay.

The manager said: "Remember that they are two players with incredible experience. Both have brought a lot into the group, and they are players I consider important.

"If anything, they have been very important on a day-to-day basis. I can understand their frustration.

"I will always be helpful and try to understand their position. They are full internationals and looking to get into their respective World Cup squads.

"So you understand that they have to play minutes. In many ways, I would love them to stay here and play their role as they have been doing until now."

Asked if he had received any approaches for either player, Martinez said: "No. Not at the moment, no."

The manager is looking to keep together his strongest possible squad ahead of a busy Christmas programme, which begins with a Premier League trip to his former club Swansea on Sunday.

There then follow home games against Sunderland on Boxing Day and Southampton on Dec. 29, before a visit to Stoke on Jan. 1.

The manager indicated earlier this week that he expected the 19-year-old to be out for "the best part of five weeks", but has been forced to revise that estimate upwards after consulting Barcelona’s medical team.

Martinez said: "Gerard is at Barcelona now. He met with the medical group at Barcelona. They contacted us straight away. We are working together in that respect, and we are going to try to make sure we get Gerard the best possible treatment and get him back as quickly as we can.

"The initial diagnosis is between six to eight weeks. We have to be careful. With any other player, I would say that maybe you can rush him back a little bit earlier. But Gerard is a sprinter, and with soft tissue injuries, we have to be very careful.

"But he will be back 100 percent fully fit. He’s already desperate to come back, which is a nice compliment."

Martinez, though, expects left-back Leighton Baines to be back for the Sunderland clash on Boxing Day, describing his imminent return as "a beautiful Christmas present".

The England international has not played since fracturing his toe during the 3-3 draw against Liverpool on Nov. 23.

Martinez said: "Leighton is not far away. He trained at the beginning of the week. We’re going to assess how he responds to that.

"I expect Leighton to be available not for this weekend, but the week after. It’s just a case of making sure we don’t rush him back too early.

"But I would say he’s not too far away, which is a beautiful Christmas present, as you can imagine.

"Leighton has already been introduced to training. We need to see how the injury reacts. If there’s no reaction, he will be available to play on Boxing Day, maybe even earlier."

Right-back Tony Hibbert, though, is not ready to return from a knee problem.

Martinez added: "We’re going to give him an extra few days individually before he joins the group, but he’s going to be joining the group on Monday. He’s not too far away."

The manager added that he would be looking to add to his squad in January to make up for the absences of striker Arouna Kone and midfielder Darron Gibson, who could both miss the rest of the season with long-term knee injuries.

He said: "I’m going to be judging how the squad is. I’ve got two long-term injuries to players who were going to have a big role -- Arouna Kone and Darron Gibson.

"They are players we are going to miss for a long period, and those are two I would like to replace for the short-term. That’s what I’m going to look into."